Line side multiplexers with protection switching

Abstract

The present invention is directed to data communication systems and techniques thereof. In a specific embodiment, the present invention provides a network connector that includes an interface for connecting to a host. The interface includes a circuit for utilizing two data paths for the host. The circuit is configured to transform the host address to different addresses based on the data path being used. There are other embodiments as well.

What is claimed is: 
     
       1. A network device comprising:
 a first plurality of circuit components comprising a first cable, the first plurality of circuit components providing a first communication path between (i) a single network interface card of a first host device and (ii) a first switch; 
 a second plurality of circuit components comprising a second cable, the second plurality of circuit components providing a second communication path between (i) the single network interface card of the first host device and (ii) a second switch, the second communication path being redundant to the first communication path, 
 wherein the first switch and the second switch are respectively coupled to the first host device via the first cable and the second cable; and 
 at least one controller configured to
 perform a conversion between a host medium access control address of the single network interface card and a first medium access control address allocated to the first host device for transfer of first data between the first host device and the first switch via the first communication path and the single network interface card, 
 detect a fault with the first communication path and, in response to detecting the fault, switch from transferring the first data via the first communication path to transferring second data via the second communication path, and 
 during transfer of the second data via the second communication path, perform a conversion between the host medium access control address of the single network interface card and a second medium access control address allocated to the first host device for transfer of the second data between the first host device and the second switch via the second communication path and the single network interface card. 
 
 
     
     
       2. The network device of  claim 1 , further comprising a connector comprising the at least one controller, the connector having a form factor according to a quad small form-factor pluggable standard. 
     
     
       3. The network device of  claim 1 , wherein:
 the first cable has a first connector configured to connect to the first switch; and 
 the second cable has a second connector configured to connect to the second switch. 
 
     
     
       4. The network device of  claim 1 , wherein the at least one controller comprises a clock signal selector configured to:
 during transfer of the first data via the first communication path, track a first clock signal associated with the first communication path and transmit the first data from the network device based on the first clock signal; and 
 during transfer of the second data via the second communication path, track a second clock signal associated with the second communication path and transmit the second data from the network device based on the second clock signal. 
 
     
     
       5. The network device of  claim 4 , further comprising a phase-lock loop circuit comprising the clock signal selector, wherein:
 a frequency of the first clock signal is different than a frequency of the second clock signal; 
 the phase-lock loop circuit is configured to generate a reference clock signal (i) based on the first clock signal during transfer of the first data, and (ii) based on the second clock signal during transfer of the second data; and 
 the at least one controller is configured to control timing of transmission of the first data and the second data based on the reference clock signal. 
 
     
     
       6. The network device of  claim 1 , wherein the at least one controller is configured to, based on which one of the first communication path or the second communication path is in use, convert the host medium access control address of the first host device to the first medium access control address or the second medium access control address for egress data output from the first host device. 
     
     
       7. The network device of  claim 1 , wherein the at least one controller is configured to, based on which one of the first communication path or the second communication path is in use, convert the first medium access control address or the second medium access control address to the host medium access control address of the first host device for ingress data being transferred to the first host device. 
     
     
       8. The network device of  claim 1 , wherein:
 the first plurality of circuit components comprises a first physical medium dependent sublayer, a first forward error correction code sublayer, and a first physical coding sublayer; and
 the second plurality of circuit components comprises a second physical medium dependent sublayer, a second forward error correction code sublayer, and a second physical coding sublayer. 
 
 
     
     
       9. The network device of  claim 1 , wherein:
 the first plurality of circuit components is connected to the first host device at a first end of the first communication path and to the first switch at a second end of the first communication path; and 
 the second plurality of circuit components is connected to the first host device at a first end of the second communication path and to the second switch at a second end of the second communication path. 
 
     
     
       10. The network device of  claim 1 , wherein:
 the first plurality of circuit components comprises a first physical medium dependent sublayer, a first forward error correction code sublayer, and a first physical coding sublayer for interfacing at the network device with the first host device, 
 the first physical medium dependent sublayer, the first forward error correction code sublayer, and the first physical coding sublayer are implemented on a host end of the second cable; 
 the second plurality of circuit components comprises a second physical medium dependent sublayer, a second forward error correction code sublayer, and a second physical coding sublayer for interfacing at the network device with the first host device; and 
 second physical medium dependent sublayer, the second forward error correction code sublayer, and the second physical coding sublayer are implemented on the host end of the second cable. 
 
     
     
       11. The network device of  claim 10 , wherein:
 the first plurality of circuit components comprises a third physical medium dependent sublayer, a third forward error correction code sublayer, and a third physical coding sublayer for interfacing with the first switch; and 
 the second plurality of circuit components comprises a fourth physical medium dependent sublayer, a fourth forward error correction code sublayer, and a fourth physical coding sublayer for interfacing with the second switch. 
 
     
     
       12. The network device of  claim 1 , wherein:
 the first plurality of circuit components comprise a first chip; 
 the second plurality of circuit components comprise a second chip; and 
 the at least one controller controls operation of the first chip and the second chip. 
 
     
     
       13. The network device of  claim 1 , wherein the at least one controller is implemented in a physical layer. 
     
     
       14. The network device of  claim 1 , wherein the conversion between the host medium access control address of the first host device and the first medium access control address and the conversion between the host medium access control address of the first host device and the second medium access control address are implemented in a physical layer and not in a layer higher than the physical layer. 
     
     
       15. The network device of  claim 1 , wherein the first plurality of circuit components comprise circuit components separate from the second plurality of circuit components. 
     
     
       16. The network device of  claim 15 , wherein the first plurality of circuit components and the second plurality of circuit components comprise circuit components shared by the first communication path and the second communication path. 
     
     
       17. The network device of  claim 1 , wherein the at least one controller detects the fault as a result of receiving a signal from the first host device, the signal instructing the at least one controller to switch from the first communication path to the second communication path. 
     
     
       18. The network device of  claim 1 , wherein:
 the first plurality of circuit components transfer the first data between the first host device and a second host device via the first switch; and 
 the second plurality of circuit components are configured to transfer the second data between the first host device and the second host device via the second switch. 
 
     
     
       19. A communication system comprising:
 the network device of  claim 1 ; 
 the first switch connected to a second host device and configured to support bi-directional communication between the first host device and the second host device; and 
 the second switch connected to the second host device and configured to support bi-directional communication between the first host device and the second host device. 
 
     
     
       20. A communication system comprising:
 the network device of  claim 1 ; and 
 the first host device configured to
 detect the fault with the first communication path, and 
 generate a signal instructing the at least one controller to switch from the first communication path to the second communication path. 
 
 
     
     
       21. A communication system comprising:
 the network device of  claim 1 ; 
 the first host device; 
 a second host device; and 
 a second network device comprising
 a third plurality of circuit components comprising a third cable, the third plurality of circuit components providing a first communication path between (i) the first switch and (ii) a second network interface card of the second host device, and 
 a fourth plurality of circuit components comprising a fourth cable, the fourth plurality of circuit components providing a second communication path between (i) the second switch and (ii) the second network interface card, the second communication path of the second network device being redundant to the first communication path of the second network device, 
 
 wherein the first switch and the second switch are respectively coupled to the second host device via the third cable and the fourth cable. 
 
     
     
       22. The communication system of  claim 21 , wherein:
 the first plurality of circuit components, the first switch, and the third plurality of circuit components are connected in series and configured to transfer the first data between the first host device and the second host device; and 
 the second plurality of circuit components, the second switch, and the fourth plurality of circuit components are connected in series and configured to transfer the second data between the first host device and the second host device. 
 
     
     
       23. The communication system of  claim 21 , wherein the second network device comprises at least one controller configured to:
 perform a conversion between a host medium access control address of the second host device and a third medium access control address allocated to the second host device for transfer of the first data between the second host device and the first switch via the first communication path of the second network device; 
 detect a fault with the first communication path and in response to detecting the fault, switch from transferring the first data via the first communication path of the second network device to transferring the second data via the second communication path of the second network device; and 
 during transfer of the second data via the second communication path of the second network device, perform a conversion between the host medium access control address of the second host device and a fourth medium access control address allocated to the second host device for transfer of the second data between the second host device and the second switch via the second communication path of the second network device.